The placement of medical devices, such as vascular stents, within the vascular system of a patient to give vessels added structural stability is a well known and increasingly common procedure. In fact, a large number of differing stents and other prosthesis have been developed for deployment within the vascular system for this purpose. In practice, devices of this nature are often inserted over a prepositioned guide wire and advanced into the vessel until the device reaches a predetermined deployment site. Generally, the route over which the stent or other device must be advanced is often long and quite frequently very tortuous.
Sometimes, during the deployment of a vascular stent or prosthesis, it may happen that the stent will be inadvertently positioned in an incorrect location. Alternatively, it may happen that a stent or other device will outlive its useful life. In these and other cases, it may become necessary to retrieve the stent from within the vascular system for removal from the patient. Unfortunately, the removal of a stent from the vascular system can be a difficult process. For one thing, removal generally requires dragging the stent back through the tortuous route by which the stent was originally deployed. When doing so, it may happen that the stent will catch, or snag, on various anatomical features within the vascular system. As a result, there is a danger that the removal process will actually traumatize the involved vessel.
The difficulty associated with stent removal is often compounded by the lack of medical instruments which are designed for the specific task of stent removal. More specifically, it is generally the case that removal of stents, and other medical prosthesis, will often be accomplished using makeshift instruments. For example, the snaring or snagging of a stent for removal from a vessel is often accomplished using a hooked instrument which has been improvised at the time of the actual procedure. As may be expected, however, expediently made instruments are often difficult to use and may cause additional vascular trauma if the hook is allowed to contact the vessel wall. Additionally, when these devices are employed, there is an ever present danger that the stent or prosthesis will become disconnected from the retrieval device during the retrieval process. A disconnection of this type further increases the difficulty and risk associated with the removal process.
In light of the above, it is an object of the present invention to provide a device for retrieving a stent from the vessel of a patient which can grip onto and hold the stent during its removal from the vessel. Another object of the present invention is to provide a device for retrieving a stent from the vessel of a patient which can minimize traumas to the vessel during the removal process. Yet another object of the present invention is to provide a device for retrieving a stent from the vessel of a patient which is simple to use, relatively easy to manufacture and comparatively cost effective.